[time-nuts] RS-232 port

Bob Benward rbenward at verizon.net
Sun Aug 9 20:05:52 EDT 2015

I am sure this has been covered, but I did have much luck in the archives.


I have an HP Z3805A with the nice faceplate and 6 leds on the front.  I also
have a Z3801A also with 6 LEDs.  What is the difference in the com ports?
The Z3805A works fine with a standard 25pin to 9 pin adapter.  The Z3801
does not.  The Z3801 was my first GPSDO and I once had it working until the
oscillator crapped out.  I recall I might have had a special com port wiring
on that unit but my memory fails me.  Can someone point the differences
between the two and can someon provide the pinouts for the Z3801A.


Also, my Z3805A is on the fritz.  Things went south after a lightning storm,
but I can't be sure the two are related.  I looked at it a few days after
the storm and it wasn't working.  The status says it is tracking two,
sometimes three sats, but it just doesn't lock.  I tried two different
antennas, no difference.  Is the GPS damaged possibly?  Any clues?




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